1. Field of the Invention
The present invention relates to heat dissipation assemblies for computers, and more particularly to a heat dissipation assembly which includes a heat sink and a backplate having a plurality of posts extending through a printed circuit board (PCB) to secure with the heat sink.
2. Description of Related Art
A computer central processing unit (CPU) is the core administrator of electrical signals in most contemporary personal computers. Continued development of CPUs has enabled them to perform more and more functions. Heat generated by CPUs has increased commensurately. Such heat can adversely affect the operational stability of computers. Measures must be taken to efficiently remove the heat from the CPU. Typically, a heat dissipation device having great heat conductivity is mounted on the CPU to remove heat therefrom. A clip is frequently used to firmly attach the heat dissipation device to the CPU, thus achieving greater efficiency of heat dissipation.
Recently developed apparatuses for attaching a heat dissipation device to a CPU include two popular means. In one such means, the heat dissipation device is placed onto a pair of retention modules. Clips engaged with the retention modules firmly attach the heat dissipation device to the CPU. Unfortunately, this attachment mechanism entails a complicated assembly procedure, and has high costs of components and assembly.
In the other such means, the heat dissipation device is directly secured by bolts onto a substrate on which the CPU is mounted. Screw holes are defined in a base of the heat dissipation device and in the substrate. The bolts are inserted into the screw holes of the heat dissipation device and the substrate. The heat dissipation device is thereby attached to the CPU. Unfortunately, the connection between the heat dissipation device and the substrate is fixed. Therefore, the forces acting on the heat dissipation device are not evenly distributed. The required precise positioning of the heat dissipation device cannot be attained. This results in the heat dissipation device not being in intimate contact with the CPU. Furthermore, the substrate and the CPU are prone to be deformed or damaged, during excessively driving the bolts.
Accordingly, an object of the present invention is to provide a heat dissipation assembly which allows a heat sink thereof to have intimate thermal contact with an integrated circuit (IC) chip.
Another object of the present invention is to provide a heat dissipation assembly which protects a printed circuit board supporting an IC chip thereon from being damaged when force is unintentionally exerted on a heat sink of the assembly that is in contact with the chip.
A further object of the present invention is to provide a heat dissipation assembly wherein fasteners of the assembly can be combined to the heat sink in advance.
In order to achieve the objects set out above, a heat dissipation assembly of the present invention comprises a heat sink, a backplate, a plurality of bolts and springs, and a PCB. The PCB supports a chip thereon and defines a plurality of through holes around the chip. The backplate forms a plurality of posts engaged in the through holes. A plurality of cavities is defined in the post. The heat sink comprises a chassis and defines a plurality of fixing holes through the chassis. The bolts extend through the fixing holes of the heat sink and threadedly engaged in the cavities of the backplate to connect the heat sink to the printed circuit board. The springs is squeezed between the bolts and the chassis of the heat sink, for providing appropriate forces on the heat sink toward the chip. In the present invention, the fasteners can be combined to the heat sink in advance by threaded engagement of the bolts with the fixing holes of the heat sink.